From this summary account of the deduction we can draw a number of conclusions: In the first place, the guiding thesis used to make sense of the argument was that the argument needed to ground not just the moral law but a cognitive framework within which the moral law is the highest law. This distinction is important since it allows us to distinguish in the practical philosophy (as in the theoretical) a level of transcendental argumentation from a level of metaphysical (...) argumentation: The concern of transcendental philosophy would be to establish the conditions of the possibility of a cognitive framework, whereas the concern of metaphysics (in Kant's sense) is to develop the principles of a given cognitive framework and to derive from them knowledge of objects (see KU, Introduction, Section V). (This distinction turns out to be invaluable in dealing with the problem of the “application” of the moral law.)In the second place, this interpretation allows us to avoid reducing the practical viewpoint to the status of a poor imitation of “real” knowledge, one whose inadequacies must be passed over in embarrassed silence for the sake of rescuing morality. If the argument is correct, practical knowledge is in one sense more firmly grounded than (and even subsumes) theoretical knowledge, even though its grounds do not allow of complete insight.And, finally, we can make at least some cautious generalizations about Kant's understanding of a transcendental argument. Two things in particular seem to characterize the deduction: (1) It is essential that the argument is concerned with a cognitive framework rather than with any specific knowledge within that framework; it is the possibility of knowledge at all that is in question, and it is that fact that requires a special kind of argument. (2) Kant's assumptions about the distinct roots of human knowledge are indispensable to the argument. The distinction between mere speculation (mere thinking, which requires only our rational faculties) and knowledge (which also requires sensibility) is essential: Without that distinction we cannot understand why the argument is necessary in the first place (since, as I argued above, we cannot see how the moral law is synthetic), nor can we understand what it means to ground a cognitive framework: Grounding a cognitive framework for Kant has turned out to involve showing how two irreducibly distinct faculties can cooperate in acts of cognition - here it is the faculty of desire and the pure will which are conceptually irreducible and for which grounds of a possible a priori unity must nevertheless be given. The fact that these two features are so central to the argument would indicate that they should be taken into consideration in any discussion of transcendental arguments framed along Kantian lines. (shrink)